TABLE 4.
Effects of expR1 or expR2 plasmids on expression of the rsmA71-lacZ fusion in E. coli in the presence of 3-oxo-C6-HL or 3-oxo-C8-HL
| Straina | Relevant characteristicsb | AHL | β-Galactosidase activity (Miller units)c |
|---|---|---|---|
| MC4100(pCL1920/pAKC1100) | Vector + rsmA71-lacZ | 715 ± 23 | |
| MC4100(pCL1920/pAKC1100) | Vector + rsmA71-lacZ | 3-oxo-C6-HL | 727 ± 15 |
| MC4100(pCL1920/pAKC1100) | Vector + rsmA71-lacZ | 3-oxo-C8-HL | 740 ± 19 |
| MC4100(pAKC936/pAKC1100) | expR1 + rsmA71-lacZ | 2,033 ± 32 | |
| MC4100(pAKC936/pAKC1100) | expR1 + rsmA71-lacZ | 3-oxo-C6-HL | 732 ± 21 |
| MC4100(pAKC936/pAKC1100) | expR1 + rsmA71-lacZ | 3-oxo-C8-HL | 2,014 ± 25 |
| MC4100(pAKC938/pAKC1100) | expR2 + rsmA71-lacZ | 3,045 ± 43 | |
| MC4100(pAKC938/pAKC1100) | expR2 + rsmA71-lacZ | 3-oxo-C6-HL | 1,201 ± 30 |
| MC4100(pAKC938/pAKC1100) | expR2 + rsmA71-lacZ | 3-oxo-C8-HL | 1,122 ± 22 |
a
Bacterial cultures were grown at 28°C in LB medium supplemented with spectinomycin and tetracycline to a concentration of ca. 100 Klett units and then were divided and placed into three flasks. 3-oxo-C6-HL (final concentration, 50 μM) was added to one flask, 3-oxo-C8-HL (final concentration, 50 μM) was added to one flask, and water was added to the third flask as a control. After 3 h of incubation at 28°C, the cultures were assayed.
b
Relevant characteristics of the genes carried by bacteria.
c
The values are means ± standard deviations for three repetitions.